Dental Matrix Devices Specific to Anterior Teeth, and Injection Molded Filling Techniques and Devices

ABSTRACT

The present invention relates to methods for the restoration of a decayed portion of an anterior tooth or re-restoration of a previously filled anterior tooth, and to dental matrices and composite resin dispensers that may be used in the methods for the restoration of a decayed portion of an anterior tooth.

CROSS-REFERENCES TO RELATED APPLICATIONS

This application is a continuation application of U.S. patentapplication Ser. No. 15/235,645 filed Aug. 12, 2016, which is adivisional application of U.S. patent application Ser. No. 12/362,280filed Jan. 29, 2009, now U.S. Pat. No. 9,414,895, which claims priorityfrom U.S. Provisional Patent Application No. 61/024,473 filed Jan. 29,2008 and from U.S. Provisional Patent Application No. 61/043,307 filedApr. 8, 2008.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH

Not Applicable.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present invention relates to methods for the restoration of adecayed portion of an anterior tooth or re-restoration of a previouslyfilled anterior tooth, and to dental matrices and composite resindispensers that may be used in the methods for the restoration of adecayed portion of an anterior tooth.

2. Description of the Related Art

Dental cavities that have spread to the dentin or have undergonecavitation are typically treated by removing the decayed portion of thetooth and thereafter filling the missing tooth structure with arestorative material such as silver (amalgam), white (resin), porcelain,or gold. Cavities that are located adjacent to neighboring teeth arecalled interproximal cavities.

When treating interproximal cavities, the dentist first removes thedecayed portion of the side of the tooth. In order to properly depositthe restorative material on the side of the tooth without undesiredleaking of the restorative material beyond the side of the tooth, thedentist places a dental matrix around at least a portion of the tooth.The dental matrix may be a metallic or plastic strip, and when thematrix is placed around at least a portion of the tooth, the matrix actsas a form for the desired shape of the restored tooth. Various dentalmatrix bands are shown in U.S. Pat. Nos. 6,712,608, 6,619,956,6,350,122, 6,142,778, 6,079,978, 5,975,906, 5,807,101, 5,730,592,5,622,496, 5,501,595, 5,460,525, 5,425,635, 5,114,341, 4,997,367,4,781,583, 4,718,849, 4,704,087, 4,601,662, 4,553,937, 4,536,155,4,523,909, 4,024,643, 3,842,505, 3,108,377, and 2,611,182, and U.S.Patent Application Publication Nos. 2006/0019217 and 2005/0089814. Thedisadvantages of these known matrix bands is that they are not trulyanatomic and therefore, they must be conformed to the tooth by pressureor other means. As a result, these matrixes are inefficient in that moredentist time is needed to complete the restoration, and the final resultmay be a non-anatomic restoration.

In the past a flat clear (e.g., Mylar™ plastic) strip was placed afterthe cavity was prepared and often adapted with an interdental wedge orelastic spacer. There have been problems with previous techniques. Theproblems with traditional clear Mylar™ plastic strips are that they areflat and require wedging, and do not conform to the tooth.

After the cavity was prepared, the composite was placed onto orpartially injected onto the tooth. The composite was then packed intothe cavity preparation.

Finally, the flat clear or metallic matrix was engaged with fingers orinstruments to wrap around the tooth, and then simultaneously a lightcure unit was placed in proximity to the tooth to initiate photo-curingor polymerization of the composite. Holding all four ends of the stripswhile simultaneously light-curing is always a challenge. The problems ofthe traditional technique included flat interdental shapes that are anesthetic and health liability. In particular, the “dark triangle” thatoften occurs is caused by insufficient buttressing of the gingivaltriangle which is seeking two approximating rounded interdental toothprofiles.

It is believed that no attempt has been made to present for a sectionalcurved and or anatomically shaped nor tooth specific matrix nor surfacespecific matrix for anterior teeth.

The anterior tooth has a complex shapes with multiple curvatures. It isasymmetrical from front side to back side (facial to lingual) and fromright to left (mesial to distal). Sectional clear flat matrix strips foranterior teeth have been available. These fillings today are performednearly universally with tooth colored filling materials (compositeresin) and require a medium to contain the filling material inside thecavity preparation. These matrix strips are translucent, and typicallymade from Mylar™ plastic material that is thin and pliable. It isbelieved that to date there are no sectional matrices available foranterior teeth other than a flat Mylar™ plastic strip.

It is believed that the only anatomic (non-flat) shaping device foranterior teeth currently sold is a strip crown that is formed from astiff material such as polycarbonate. They are used for temporization orbuilding up of a severely broken down tooth. Composite material isplaced inside of the strip crown, cured with light or chemicalpolymerization, and then the polycarbonate can be stripped away (in thecase of a long term “build-up”, such as is done until permanentdentistry is undertaken) leaving a tooth built up with composite. Therelatively crude shape of the buildup is then eventually prepared(ground down) to the peg shape typically performed in preparation for aveneer-crown. A crown is then fabricated in a laboratory or with CAD CAMand then the tooth receives a crown to permanently cover the “build-up”.Alternatively the strip crown can be left in place as a temporary veneercrown. The thickness and stiffness of the “strip crown” disallows itsuse for interproximal fillings. Hence the use of flat Mylar™ plasticstrips is the norm today.

Some problems with current flat plastic matrix strips for anterior teethinclude: (1) the flat plastic matrix strips are flat (not anatomic),requiring crimping; (2) the flat plastic matrix strips requirestabilizing with wedges or other devices; (3) the flat plastic matrixstrips require further stabilizing with the operator's fingers or thedental assistant's fingers, and back to back fillings (two neighboringteeth with interproximal caries or failing fillings) present extremechallenges to manipulate four matrix ends simultaneously; (4) the flatplastic matrix strips require that the strip be “wrapped” to approximatethe tooth after placement of filling material (such as a composite,glass ionomer, composite/glass ionomer mix) and prior to polymerizationor light curing of the material; (5) time and energy is usually expendedto remove excess and areas of bulky, non anatomic regions of thecomposite filling material because of the residual contour created bythe flat, non anatomic clear strip; (6) the above mentioned finishingcan lead to gum trauma and can lead to iatrogenic gouging of toothsurface and tooth surfaces of neighboring teeth; (7) the above mentionedfinishing disturbs the smooth and highly cured surface left by theplastic strip and while this disturbed surface can be polished, it isvirtually impossible to return to the original smoothness and thesesurfaces are manifested clinically as a matte finish, rough finish, orjagged finish and these three imperfect finish types collect bacteriamore readily, are more prone to discoloration and predispose the toothto decay and predispose the periodontal attachment (gum and bone) todeterioration from the destructive nature of periodontal diseases; (8)the flat matrix strip combined with a wedge often results in a flatcontoured filling that has an unsightly gapping (dark triangle) betweenthe teeth at the gum attachment area such that food and bacterialaccumulation are also more common in these gaps; and (9) the pre curvedsectional matrix bands for posterior teeth are too short to be usedeasily on anterior teeth as matrix bands for posterior teeth range from4.5 millimeters to 6.5 millimeters in height, and the needs of anteriorteeth range approximately from 8 millimeters to 13 millimeters inheight.

Thus, there is a need for improved dental matrices, particularly dentalmatrices intended for anterior teeth.

As detailed above, removed tooth structure is often filled with acomposite restorative material such as white filled resin. Whileflowable composites have been available for quite some time and canprovide for ease of filling intricate dental cavity preparations, theability of paste composite material to flow and adapt to the intricaciesof a dental cavity preparation can be compromised if the viscosity ofthe paste composite is too high. Thus, paste composite can posedifficulties in advanced injection molded cavity preparation and fillingtechniques such as that described in U.S. Patent Application PublicationNo. 2008/0064012. However, in comparison to flowable composite, pastecomposite has been shown to be superior in that paste composite has lesspolymerization shrinkage, less wearing over years of mastication,improved polishability, and improved strength.

It has been proposed that dental materials can be heated before orduring extrusion to reduce viscosity so that the restorative materialexpressed from a dental capsule can better adapt to the walls of acavity preparation and to the intricacies of the cavity preparation.See, for example, U.S. Pat. Nos. 6,312,254, 6,320,162, 6,616,448 and7,097,452. Although some benefits of heated composite materials havebeen reported in these patents, adoption of this technique has been verylimited. Composite manufacturers have not adopted significant changes totheir delivery systems to capitalize on the concept and benefits ofheated composite. For example, the tip orifice size of typical currentpaste composite syringes (examples include Filtek Supreme Plus™available from 3M, St. Paul, Minn., USA) is significantly larger thanthe orifice tip size of the flowable type composites. In the case ofthis example product from 3M, the paste syringe orifice is approximately2.5 millimeters in diameter, while the 3M flowable composite tip size isless than 1 millimeter. See also, U.S. Pat. No. 7,001,932 in which acomposite is filled in a syringe having an internal tip diameter of 2millimeters.

Accordingly, it can be appreciated that in the field of composite dentalrestorative materials, there is a need for improved composite dispensersand methods such that paste composite can have its handlingcharacteristics improved to handle more like the less robust but easierto apply flowable composites.

SUMMARY OF THE INVENTION

The invention meets the foregoing needs by providing improved methods,dental matrices, composite dispensers, and kits for the restoration of adecayed portion of an anterior tooth.

In one aspect of the invention, there is provided a dental matrixincluding a non-flat sectional strip dimensioned for anterior teeth. Thematrix can be anatomic. The matrix can be translucent. The matrix can bepre-curved and universal for any interproximal surface of any anteriortooth. The matrix can include one or more anatomic features. The matrixcan include a pronounced root-crown interface. In one form, the matrixis side specific. The matrix can be labeled as upper anteriortooth-right side, upper anterior tooth left side, lower anterior toothright side or lower anterior tooth left side. The matrix can be toothspecific (e.g., maxillary right central incisor). The matrix can betooth and surface specific (e.g., upper right central incisor, mesialsurface). The matrix can be fully anatomic (as opposed to simplypre-curved or having one or more anatomic features). The matrix can beanatomically shaped such that the matrix is self stabilizing and handsfree. The matrix can include a side flange that extends away from thetooth.

In another aspect, the invention provides a dental matrix including anon-flat sectional strip having a first end and an opposed second end.The strip includes at least one anatomic feature, and the strip has alength from the first end to the second end such that the strip cancover from 90 degrees up to 359 degrees around a side surface of a toothcovered by the strip. The strip can have a length from the first end tothe second end such that the strip can cover from 90 degrees up to 270degrees around the side surface of the tooth covered by the strip. Thestrip can have a length from the first end to the second end such thatthe strip can cover from 90 degrees up to 180 degrees around the sidesurface of the tooth covered by the strip. The strip can have a lengthfrom the first end to the second end such that the strip can cover from90 degrees up to 120 degrees around the side surface of the toothcovered by the strip. The strip can be dimensioned for anterior teeth.The matrix can be translucent. The matrix can be pre-curved anduniversal for any interproximal surface of any anterior tooth. Thematrix can be tooth specific. The matrix can be tooth and surfacespecific. The matrix can be fully anatomic.

In yet another aspect, the invention provides a dental matrix includinga non-flat sectional strip having a first end and an opposed second end.The strip includes at least one anatomic feature, and the strip has alength from the first end to the second end such that the strip cancover 360 degrees around a side surface of a tooth covered by the strip.The strip can have a length from the first end to the second end suchthat the strip can cover from 360 degrees up to 420 degrees around theside surface of the tooth covered by the strip. The matrix can betranslucent. The matrix can be pre-curved and universal for anyinterproximal surface of any anterior tooth. The matrix can be toothspecific. The matrix can be tooth and surface specific. The matrix canbe fully anatomic.

In still another aspect, the invention provides an injection moldedtooth restoration method that can only be accomplished with a relativelyprecise fit of any of the preceding matrices according to the inventionto the tooth being restored.

In yet another aspect, the invention provides a method for therestoration of a tooth having an original shape including aninterproximal surface. The method includes: (a) removing a portion ofthe interproximal surface of the tooth to form a hollow cavitypreparation; (b) surrounding the removed portion of the interproximalsurface of the tooth with any of the preceding matrices according to theinvention; (c) placing a light-curable resin tooth bonding agent intothe cavity preparation; (d) extruding a heated light-curable pastecomposite resin into the pool of the flowable composite before lightcuring the pool of the flowable composite; and (e) simultaneously lightcuring the bonding agent and the paste composite resin contained in thecavity preparation. Step (d) can comprise extruding the paste compositeresin through a step down tip. Step (d) can comprise extruding the pastecomposite resin through a step down tip inserted into a compositecapsule. Step (d) can comprise extruding the paste composite resinthrough a step down tip inserted into a composite capsule wherein thetip has a rib to resist dislodgement from the capsule.

In still another aspect, the invention provides a dental compositedispenser including a housing including an end section for dispensingcomposite; an electrical power supply; at least one resistive heatingelement in electrical communication with the power supply where eachheating element is located in the end section of the housing; and asource of composite in the end section of the housing. The source ofcomposite includes a removable hollow step down tip through which heatedcomposite flows out of the source of composite. In one form, the stepdown tip has an inside diameter in the range of about 0.4 millimeters toabout 1.6 millimeters. The source of composite can be a capsule or asyringe, or a chamber in the end section of the housing. In one form,the source of composite is a capsule, and each heating element islocated only near the tip of the capsule. In another form, the source ofcomposite is a syringe, and the housing includes a plunger sized toexpress composite from the syringe. In another form, the electricalpower supply includes an AC power cord. In another form, the electricalpower supply includes a battery.

In still another aspect, the invention provides a method for dispensingcomposite from a dental composite dispenser. The method includes:loading a source of composite in the end section of the dispenser;inserting a hollow step down dispensing tip in the source of composite;and extruding composite out of the tip. The source of composite can beheated before extruding composite out of the tip. The step down tip canhave an inside diameter in the range of about 0.4 millimeters to about1.6 millimeters.

Thus, this aspect of the invention includes the manufacture of removabledispensing tips that have tip sizes and shapes specific to the extrusionof paste composite dental filling material that has been pre-warmed ordirectly altered during extrusion, the alteration of the physicalcharacteristics of the composite from heat and/or extreme pressure; orother means of altering the physical properties to allow increasedflowability of the paste composite. These tips can be (i) fastened tothe composite heating extrusion gun, (ii) warmed and/or fastened topre-warmed syringes, or (iii) fastened to traditional hand helddispensing guns; which then together have been pre-warmed in a warmingdevice. The small removable tips with a reduced tip orifice size allowfor: (i) the direct placement into cavities that are smaller than thecircumference of traditional paste capsule tip orifice size, (ii) aninjection molded composite technique which requires deeper insertion ofthe capsule tip into the cavity preparation, and (3) use with anatomicand pre-curved matrices that impede the insertion of larger, traditionaltip orifices. The invention satisfies a need for a system that includessmall removable dispensing tips for extruding paste composite through anorifice size that requires a physical change of the paste, including butnot limited to heat and high pressure. Many of the paste compositesexperience a phenomenon of being thixotropic, i.e., the pastetemporarily flows better with reduced viscosity. Thus, a capsule withremovable tips of small orifice size for paste composite has manyadvantages.

In yet another aspect, the invention provides a dispenser for supplyinga dental restorative material to a cavity preparation. The dispenserincludes a hollow body having an inner surface and a proximal opening ata proximal end of the body. The dispenser includes a movable pistonengaging the inner surface of the body where the piston seals theproximal opening of the body. The piston and the inner surface define aninterior space of the body. The dispenser includes a hollow dispensingorifice having a passageway extending from an inlet to an outlet wherethe inlet is in fluid communication with the interior space of the body.The dispenser includes a dental restorative material in the interiorspace of the body where the dental restorative material is a pastecomposite including a resin and a filler. Movement of the piston towardthe dispensing orifice extrudes dental restorative material from theoutlet of the dispensing orifice. The passageway of the dispensingorifice can have an inside diameter in the range of about 0.4millimeters to about 1.8 millimeters.

This aspect of the invention is a preloaded body (e.g., a capsule) thatis designed to be used in conjunction with heated extrusion, or extrudedwith forces that are greater than currently produced with current handlever type dispenser systems. In other words, this aspect of theinvention is any packaging of paste composite into a delivery systembody (e.g., unidose capsules, syringes with removable or fixed tips,tubs, tips, mixing tips (i.e., for A-B chemical cure, or dual cure withA-B chemical cure plus light cure) where the dispensing orifice sizerequires heat or extreme pressure to allow it to work.

Thus, this aspect of the invention includes the manufacture andplacement of paste composite dental filling material into preloadedunidose type capsules; capsules which possess reduced tip orifice sizethrough which the extrusion of the paste composite through the smallerdispensing orifice is dependent on alteration of the physicalcharacteristics of the paste composite from heat and/or extreme pressureor other means by which the physical properties of the paste compositeare altered to allow increased flowability (such as vibration,ultrasonic energy, microwaves, or similar physical and thermalenergies). The small dispensing orifice with a reduced tip orifice sizeallows for: (i) the direct placement into cavities that are smaller thanthe circumference of traditional paste capsule tip orifice size, (ii) aninjection molded composite technique which requires deeper insertion ofthe capsule tip into the cavity preparation, and (3) use with anatomicand pre-curved matrices that impede the insertion of larger, traditionaltip orifices.

This aspect of the invention further includes the manufacture ofdisposable capsules with a reduced tip dispensing orifice size, forsubsequent loading of a pre-measured amount of paste composite dentalfilling material, the extrusion of which through the smaller dispensingorifice is dependent on alteration of the physical characteristics ofthe paste composite from heat and/or extreme pressure; or other means ofaltering the physical properties to allow increased flowability of thepaste composite. The wall of the dispensing orifice can be thicker thanthe inside diameter of the passageway of the dispensing orifice to be ofincreased strength to withstand the increased pressure. This aspect ofthe invention satisfies the need for a preloaded paste composite capsulewith a small dispensing orifice. That is because paste composites aretoo viscous to be extruded or injected through smaller orifices. Theinvention satisfies a need for a system that includes small dispensingorifices for extruding paste composite through an orifice size thatrequires a physical change of the paste, including but not limited toheat and high pressure. Many of the paste composites experience aphenomenon of being thixotropic, i.e., the paste temporarily flowsbetter with reduced viscosity. A capsule according to the invention witha dispensing orifice with reduced tip orifice size for paste compositehas the advantages of the above mentioned tips. Extreme pressure isdefined as pressure beyond what is currently produced in the availabledispensing guns with manual levers. Heat is defined as temperaturesabove room temperature, preferably from 70° F. to 180° F. This increasedtemperature can produced either in hot plates, or dedicated compositepre-warmers such as that shown in U.S. Patent Application PublicationNo. 2004/0234921, or in the direct heating as in versions of the presentinvention.

In still another aspect, the invention provides for the manufacture of adental composite filling material with altered filler particlecomposition that utilizes (i) elevated filler particle content by weightand/or volume, or (ii) particle shape modification, or (iii)modification of particle configuration such as pre-sintering, or (iv)utilization of pre-cured heavily filled composites which are then groundand re-mixed with uncured composite with a more usable fillerpercentage, or (v) altered chemistry of the organic binding resin (e.g.,a Bis-GMA or silorane), to achieve minimized polymerization shrinkage,less than 1% and approaching 0%, and the placement of the composite mayonly be possible if it were heated and/or extreme pressure, vibration,ultrasonic energy, microwaves, or similar physical and thermal energieswere applied prior to placement to achieve this temporary reduction inviscosity and thixotropic (sheer thinning) affect.

It is one advantage of the invention to provide a composite dispenser inwhich paste composite can be treated to act like flowable composite whenfilling a cavity preparation. The composite dispenser allows pastecomposite to be used in injection molded cavity preparation and fillingtechniques with better handling and placement. The composite dispenseralso allows paste composite to be used to fill smaller cavitypreparations. In addition, the small orifice diameter of the compositedispenser applies shear stresses to the paste composite that lower theviscosity of the paste composite.

It is another advantage of the invention to provide a compositedispenser in which paste composite can be substituted for flowablecomposite when filling a cavity preparation. The use of paste compositeovercomes the problems of flowable composite such as the increaseshrinkage of flowable composites, the lower polishability of curedflowable composite, the lower wear resistance of cured flowablecomposite, and the lower strength of cured flowable composite.

It is yet another advantage of the invention to provide a method offilling a cavity preparation using an anatomic matrix and a compositedispenser in which paste composite can be substituted for flowablecomposite. Previous techniques for placement of the paste composite arenot truly injection molded. Rather they are placed with a small spatula,layered and or packed. Prior matrices do not allow injection moldingbecause they are not anatomically shaped and or the cavity shape doesnot support an injection molded technique. Additionally, the lack oftranslucency of the matrix demands incremental loading. Also, the tipsizes of the composite syringes are too large to insert deep enough intothe cavity shapes. Injection molding can be accomplished by modifyingthe pressure applied during composite delivery, or modifying thetemperature and/or thixotropic state of a paste composite to allow it tobe injected without the use of lesser filled resins such as flowableresin.

It is still another advantage of the invention to provide a compositedispenser in which paste composite can be substituted for flowablecomposite when filling a cavity preparation. The paste composite can besuper filled or otherwise modified such that it would be so heavy andthick that the dentists would have trouble placing it using conventionaltechniques. The paste composite is heated and extruded so that it actslike normal paste. For an injection molding technique, the pastecomposite will work readily, whereas with the old fashioned approach ofspooning paste composite or packing paste composite into the tooth, thepaste composite could begin to cool and thicken and become unusablebefore the dentist finished placing it. The heavy viscosity is a benefitin the injection molded technique.

The features, aspects, and advantages of the present invention willbecome better understood upon consideration of the following detaileddescription, drawings and appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a right side view of a human left central incisor.

FIG. 1B is a front view of a human left central incisor.

FIG. 2A is a right side view similar to FIG. 1A showing an area ofinterproximal decay or of a previously placed filling.

FIG. 2B is a front view similar to FIG. 1B showing an area ofinterproximal decay or of a previously placed filling.

FIG. 3A is a right side view similar to FIG. 1A showing a side specificmatrix on the left central incisor.

FIG. 3B is a front view similar to FIG. 1B showing a side specificmatrix on the left central incisor.

FIG. 3C is a cross-sectional view taken along line 3C-3C of FIG. 3B.

FIG. 4A is a right side view similar to FIG. 1A showing a matrix on theleft central incisor, the matrix being a universal sectional type matrixfor anterior teeth with multiple anatomic features but not side orsurface specific.

FIG. 4B is a front view similar to FIG. 1B showing a matrix on the leftcentral incisor, the matrix being a universal sectional type matrix foranterior teeth with multiple anatomic features but not side or surfacespecific.

FIG. 4C is a cross-sectional view taken along line 4C-4C of FIG. 4B.

FIG. 5A is a perspective view of a pre-curved matrix specific toanterior teeth with one anatomic feature.

FIG. 5B is an inverted side view of the pre-curved matrix of FIG. 5A.

FIG. 6 is a side view of a composite delivery gun and yet to be insertedcapsule in which composite resin composite filling material ispre-loaded.

FIG. 7 shows the capsule inserted into the delivery gun of FIG. 6 andready for expressing into a cavity preparation.

FIG. 8 is an enlarged side view of the capsule of FIG. 6.

FIG. 9 is a vertical cross-sectional view of the capsule of FIG. 6showing the position of plunger and the pre-loaded resin compositefilling material.

FIG. 10 is a view similar to FIG. 9 showing the extrusion of the resincomposite material as the plunger is driven into the barrel of thecapsule and pressure is applied to the resin composite.

FIG. 11 shows a step-down tip before insertion in the end of the capsuleof FIGS. 6-10.

FIG. 12 shows the step down tip being inserted in the capsule of FIGS.6-10.

FIG. 13 shows the step down tip fully inserted into the capsule of FIGS.6-10.

FIG. 14 shows four varieties of the step down tips.

FIG. 15 shows a view taken along lines 15-15 of FIG. 7 showing oneversion of a composite dispenser having means for heating the capsule ofFIGS. 6-10.

FIG. 16 is a view similar to FIG. 15 showing another version of acomposite dispenser having means for heating the capsule of FIGS. 6-10.

FIG. 17 is a side view of a commercially available syringe for supplyingcomposite resin.

FIG. 18 is a view similar to FIG. 15 showing another version of acomposite dispenser having means for heating the syringe of FIG. 17.

FIG. 19 is a view similar to FIG. 15 showing another version of acomposite dispenser having means for heating a chamber that is filedwith composite resin.

FIG. 20 is a side view, partially in cross-section, of a capsuleaccording to the invention for supplying a dental restorative materialto a cavity preparation.

Like reference numerals will be used to refer to like parts from Figureto Figure in the following description of the drawings.

DETAILED DESCRIPTION OF THE INVENTION

The invention provides improved methods, dental matrices, compositedispensers, and kits for the restoration of a decayed portion of ananterior tooth.

In an example method according to the invention for the restoration of atooth, the dentist locates a tooth having a cavity. A hollow cavitypreparation is prepared in a tooth. The tools and techniques for formingthe hollow cavity preparation are well known in the art and thereforewill not be explained further.

In order to properly deposit the restorative material on the side of thetooth without undesired leaking of the restorative material beyond theside of the tooth, the dentist places a dental matrix around at least aportion of the tooth. In the invention, a sectional anatomic translucentdental matrix is placed on the tooth. When the matrix is placed aroundat least a portion of the tooth, the matrix acts as a form for thedesired shape of the restored tooth.

The cavity preparation in the tooth is then etched with liquid and/orgel phosphoric acid. The cavity preparation in the tooth is then rinsedand dried. A lightly filled or unfilled light curable resin toothbonding agent is then applied to the tooth covering the entire cavitypreparation. The resin tooth bonding agent is then air thinned except onthe tooth surface where a small pool of resin tooth bonding agent ismaintained. The resin tooth bonding agent is not light cured at thispoint. Resin tooth bonding agents improve composite to enamel and/ordentin bonding. One example resin tooth bonding agent is available underthe tradename OptiBond Solo Plus®.

A light curable flowable composite resin is then injected directly intothe pool of resin tooth bonding agent (under magnification if possible)without incorporating bubbles. A tiny amount of the light curableflowable composite resin is expressed before placement to ensure thatthere is no air in the cannula. The light curable flowable composite andresin tooth bonding agent are not light cured at this point. Generally,light curable flowable composite resins contain 20-25 percent lessfiller in the light curable polymeric material than nonflowable pastematerials. Light curable flowable composite resins are available undertradenames such as Filtek™, Flow-It™, EsthetX®, Revolution®, AeliteFlo®,PermaFlo®, Dyract Flow®, Tetric®, and Heliomolar®. Light curable resinsare preferred as light cured resins are more color stable thanchemically cured resins.

A light curable paste composite resin is then extruded into the pool offlowable composite resin and resin tooth bonding agent without creatingair bubbles, allowing the composite resin to displace most of the lesserfilled flowable composite resin and resin tooth bonding agent (undermagnification if possible). Composite resins are available undertradenames such as 3M Z100™, 3M Filtek Supreme™, and Prodigy®. The nextsteps are burnishing, carving the anatomy and carving excess composite.There is no need to use a condenser or plugger.

The filled cavity preparation is then cured using a curing light such ashigh intensity light emitting diode (LED) lights, plasma-arc curinglights, halogen lights, and laser lights. The matrix is then removed,and the restored tooth is polished with discs, strips, and rubber tippedand carbide burs.

Optionally, flowable composite resin is not used in the method. In thisversion of the method, heating the paste composite allows the morehighly filled paste composite to be expressed through step down tipsaccording to the invention having smaller inside diameters (about 0.4millimeters to about 1.6 millimeters).

Looking at FIGS. 1A-5B, there is shown the lingual, (palatal or inside)surface 1 of a left central incisor (LCI), or anterior tooth. The crosshatched area 2 is an area of interproximal decay or of a previouslyplaced filling. The facial (buccal or outside) surface 3 of tooth LCI isalso shown. The cemento-enamel junction (crown-root interface) is shownat 5.

Various matrices are provided by the invention. Each matrix can be toothspecific, or the matrix can be tooth type specific, or the matrix can betooth surface specific. By “tooth specific” it is meant that the matrixis configured to conform to the shape of the outer surface of thespecific natural tooth being restored such as (without limitation) anupper left central incisor. By “tooth type specific” it is meant thatthe matrix is configured to conform to the shape of the outer surface ofthe specific type of natural tooth being restored such as (withoutlimitation) an upper incisor. By “tooth surface specific” it is meantthat the matrix is configured to conform to the shape of the outersurface of the specific natural tooth surface being restored such as(without limitation) an upper left incisor mesial surface.

In FIGS. 3A and 3B and 3C, a side specific matrix 6 for anterior teethis shown. The matrix 6 has a side terminal flange 3 f that extends awayfrom the surface of the tooth LCI when the matrix 6 is placed on thetooth LCI. This example would be designated as right side or right handspecific. “Mesial and Distal” orientation is the common anatomicdescription but the side specific, “right hand” or “right side” namingsignifies that the matrix can be used only on the right side of thetooth, which would be the distal surface of a right maxillary (upper)central incisor, or a right maxillary lateral incisor or a rightmaxillary canine tooth. Conversely the “right hand specific anteriormatrix” would be used for the mesial surface of a maxillary left centralincisor, or a maxillary left lateral incisor, or a maxillary left caninetooth. The mandibular (lower) anterior teeth would be the inverseorientation of the maxillary teeth. They are labeled as “right hand” or“left hand” specific to account for the asymmetrical shape of the tooth.In this variation, the cingulum shape of the lingual surface isrepresentational and therefore the matrix is not universal and thereforethe operator must choose the specific matrix and orientation for thematrix.

In FIGS. 4A and 4B, a universal sectional type matrix 4 for anteriorteeth with multiple anatomic features but not side or surface specificfeatures is shown.

The matrix 4 has a root-crown interface 8 and a side terminal flange 4 fthat extends away from the surface of the tooth LCI when the matrix 4 isplaced on the tooth LCI. The matrix 4 can be translucent, sectional,and/or anatomically shaped. The matrix 4 as shown is partially anatomic(i.e., it is less than all anatomic). However, a fully anatomic matrixis also in accordance with the invention. By “anatomic”, it is meantthat the matrix has an inner surface that conforms to the shape of theouter surface of the region of the natural tooth being restored.

The sectional matrix 4 can cover from 90 degrees up to 359 degreesaround the lingual side surface 1 and the facial side surface 3 of thetooth LCI. Preferably, the sectional matrix 4 can cover from 90 degreesup to 270 degrees around the lingual side surface 1 and the facial sidesurface 3 of the tooth LCI. More preferably, the sectional matrix 4 cancover from 90 degrees up to 180 degrees around the lingual side surface1 and the facial side surface 3 of the tooth LCI. Most preferably, thesectional matrix 4 can cover from 90 degrees up to 120 degrees aroundthe lingual side surface 1 and the facial side surface 3 of the toothLCI. Alternatively, a 360 degree partially anatomic or fully anatomicmatrix that can either be continuous or with a cut can be provided. Inanother alternative, a 360 to 420 degree partially anatomic or fullyanatomic matrix with a cut and purposeful overlap to accommodatedifferent variations in circumference of teeth that is seen betweendifferent individuals can be provided.

In FIGS. 5A and 5B, there is shown, a side view of a pre-curved matrix 7specific to anterior teeth with one anatomic feature which is theroot-crown interface 8 a. In the example matrix 7 of FIGS. 5A and 5B,the length L of the pre-curved matrix 7 is approximately 13 millimetersand the height H can range approximately from 10 millimeters to 13millimeters.

A matrix according to the invention can be anatomically shaped such thatthe matrix is hands free and self stabilizing (i.e., there is norequirement for a matrix stabilizer that conforms the matrix to thetooth). However, in a two step process, a dentist can forgo the use of amatrix stabilizer for the first step when the cavity is deep and or onthe root surface and first apply flowable composite and/or pastecomposite to create an undercut that will allow the subsequent use of amatrix stabilizer with more ease in a single step injection moldingtechnique to finish the filling.

In FIGS. 6-19, there are shown various dental composite dispensersaccording to the invention. FIG. 6 shows a side view of a dentalcomposite dispenser gun 11 and a yet to be inserted capsule 15 in whichthe resin composite filling material is pre-loaded. FIG. 7 shows thecapsule 15 inserted into the dispenser gun 11 and ready for expressinginto a cavity preparation. The piston 17 drives the rubber plunger 21which in turn presses the paste composite resin filling material. Thehandle 12 of the dispenser gun 11 in FIG. 7 has been pressed and iscompressing the spring 13. Hinge 14 allows rotation of the handle 12 topress the piston 17. FIG. 8 is a side view, close up of the capsule 15having a dispensing orifice 19 with inside diameter O (which can be 2.5mm.) and a rear end 20. FIG. 9 is a cross-sectional view of the capsule15 showing the position of plunger 21 and the pre-loaded resin compositefilling material 23 (shown with cross hatching) which moves forward byway of a rear sliding disc 22. FIG. 10 shows the extrusion of the resincomposite material 23 as the plunger 21 is driven into the barrel of thecapsule 15 and pressure is applied to the resin composite 23.

FIG. 11 shows a step-down tip 24 according to the invention approximatedto the capsule 15 before insertion. The dispensing orifice 25 of the tip24 is a smaller orifice size O′, which diameter can range fromapproximately 0.75 millimeters to 1.5 millimeters. In FIG. 11, the stepdown tip 24 is drawn to represent the 1.25 millimeter diameter orifice,which is half the diameter of the size of the dispensing orifice 19 ofthe example capsule 15 in FIGS. 6-13. FIG. 12 shows the step down tip 24being inserted in the capsule 15, which can be accomplished with fingerpressure or with dental pliers or hemostats or with common needle nosepliers. FIG. 13 shows the step down tip 24 fully inserted into thecapsule 15. Note how the annular rib 26 of the tip 24 forms a distendedwall section 27 in the capsule 15 that creates the retention needed toretain the step down tip 24.

FIG. 14 shows four non-limiting examples of the step down tips. In stepdown tip 24 a, the orifice Size 18 is in the 1 to 1.5 millimeter rangefor the inside diameter. In step down tip 24 b, the orifice Size 19 isfor ultraconservative cavities or hard to reach cavities and generallyranges in the 0.75 to 1 millimeter diameter size for the insidediameter. In step down tip 24 c, the orifice Size 20 is ovoid (about 1×2millimeters or 1×3 millimeters inside dimension) for class II cavitypreparations or other applications where a non round expressed resincomposite shape is desired. In step down tip 24 d, the orifice size isribbon shaped R with about 0.5×3 millimeters inside dimension. Theribbon shape is good for restorative fillings as a veneer layer ofcomposite, or a ribbon to line a porcelain onlay or veneer for bondedesthetic porcelain dentistry.

Turning now to FIG. 15, there is shown a dental composite dispenser 11 aaccording to the invention. The dental composite dispenser 11 a includesa housing including an end section 30 for dispensing composite. Thepiston 17 drives the rubber plunger 21 which in turn presses the pastecomposite resin filling material from the capsule 15 as described abovefor dispenser 11. The end section 30 has an opening 31 defining a space33 in which the capsule 15 may be inserted into place as shown in FIG.15. Resistive heating elements 35 are positioned in the end section 30adjacent installed capsule 15. The heating elements 35 are in electricalcommunication with an electrical power supply 37 (batteries in FIG. 15but AC corded power is also usable). The dispenser 11 a includes aswitch 38 for supplying electrical power to the heating elements 35 forgenerating heat adjacent the capsule 15 to heat up the compositematerial in the capsule 15 before expressing the composite from thehollow step down tip 24 e (having an inside diameter in the range ofabout 0.4 millimeters to about 1.6 millimeters) of the dispenser 11 a.Heating the composite allows more highly filled composites (e.g., paste)to be expressed through the step down tips having smaller insidediameters (about 0.4 millimeters to about 1.6 millimeters). In oneversion of the invention, the capsule 15 is formed from a plastic havinghigher heat transfer capabilities.

Referring now to FIG. 16, there is shown a dental composite dispenser 11b according to the invention. The dental composite dispenser 11 bincludes a housing including an end section 30 b for dispensingcomposite. The piston 17 drives the rubber plunger 21 which in turnpresses the paste composite resin filling material from the capsule 15as described above for dispenser 11. The end section 30 b has an opening31 b defining a space 33 b in which the capsule 15 may be inserted intoplace as shown in FIG. 16. Resistive heating elements 35 a arepositioned only at the tip of the end section 30 b adjacent the distalend of the installed capsule 15 to create a heating zone 41 at thedistal end of the installed capsule 15. The heating elements 35 a are inelectrical communication with an electrical power supply 37 (batteriesin FIG. 16 but AC corded power is also usable). The dispenser 11 bincludes a switch 38 for supplying electrical power to the heatingelements 35 a for generating heat adjacent the capsule 15 to heat up thecomposite material in the capsule 15 before expressing the compositefrom the hollow step down tip 24 e (having an inside diameter in therange of about 0.4 millimeters to about 1.6 millimeters) of thedispenser 11 b.

Turning to FIG. 17, there is a side view of a commercially availablesyringe 43 for supplying composite resin. The syringe 43 includes aplunger 44 having a threads 44 s that is threadingly inserted in theopen end 45 o of hollow barrel 45. By rotating the plunger 44, theplunger 44 advances in the barrel 45 to extrude composite from the tip46 of the syringe 43.

Referring now to FIG. 18, there is shown a dental composite dispenser 11c according to the invention. The dental composite dispenser 11 cincludes a housing including an end section 30 c for dispensingcomposite. The end section 30 c has an opening 31 c defining a space 33c in which the barrel 45 of the syringe 43 of FIG. 17 may be insertedinto place as shown in FIG. 18. The piston 17 drives the rubber plunger21 which in turn presses the paste composite resin filling material fromthe barrel 45. Resistive heating elements 35 b are positioned adjacentbarrel 45 to create a heating zone 47. The heating elements 35 b are inelectrical communication with an electrical power supply 37 (batteriesin FIG. 18 but AC corded power is also usable). The dispenser 11 cincludes a switch 38 for supplying electrical power to the heatingelements 35 b for generating heat adjacent the barrel 45 to heat up thecomposite material in the barrel 45 before expressing the composite fromthe barrel 45 through passage 48 and into hollow step down tip 24 f(having an inside diameter in the range of about 0.4 millimeters toabout 1.6 millimeters) of the dispenser 11 c.

Turning now to FIG. 19, there is shown a dental composite dispenser 11 daccording to the invention. The dental composite dispenser 11 d includesa housing including an end section 30 d for dispensing composite. Theend section 30 d has an opening 31 d defining a space 33 d. The endsection 30 d has an a chamber 51 with a fill hole 53 for acceptingcomposite material. After composite is filled into the chamber 51, thepiston 17 drives the rubber plunger 21 with plunger head 55 which inturn presses the paste composite resin filling material from the chamber51. Resistive heating elements 35 c are positioned adjacent chamber 51to create a heating zone 56. The heating elements 35 c are in electricalcommunication with an electrical power supply 37 (batteries in FIG. 19but AC corded power is also usable). The dispenser 11 d includes aswitch 38 for supplying electrical power to the heating elements 35 cfor generating heat adjacent the chamber 51 to heat up the compositematerial in the chamber 51 before expressing the composite from thechamber 51 through passage 57 and into hollow step down tip 24 g (havingan inside diameter in the range of about 0.4 millimeters to about 1.6millimeters) of the dispenser 11 d.

Based on the description above of the example dental compositedispensers 11 a, 11 b, 11 c, 11 d, it can be appreciated that the dentalcomposite dispensers can include an AC power cord or be cordless(include a battery). The switch 38 of the example dental compositedispensers 11 a, 11 b, 11 c, 11 d can include appropriate electricalcircuitry such that the heat of the composite can include multiplesettings for heat (e.g., 99° F., 130° F., 155° F. or 180° F.) or theheat setting can be variable from 99° F. to 180° F. In FIG. 16, thedispenser 11 b can only heat the composite as it exits, therefore notheating the whole capsule 15. The advantage is that the eventualdeterioration of the composite from extended and multiple heatings isavoided. With respect to FIGS. 17 and 18, generally a syringe 43 canprovide composite to multiple appointments or multiple fillings. Acapsule 15 by contrast will only do one or two or three fillings atmost. Some fillings require two or more capsules 15 because of thecapsule's small size. In FIG. 19, paste composite can be dumped from atub or a syringe 43 into the chamber 51, then the composite is heated inthe chamber 51 and extruded through assorted tips, generally 14 needlegauge up to 20 needle gauge and also non round orifice ribbon shape orovoid. Because the chamber requires maintenance, it may be preferred touse a disposable chamber that you dump into or a syringe 43 that youload in the dispenser after removing the twisty plunger 44 and use thestraight plunger 21 of the dispenser to force composite out of thesyringe 43. Of course, a capsule 15 that conforms to the dispenser isalso suitable. One can also use a unidose capsule that either has stepdown tip or the manufacturer of the composite makes preferred orificesizes. Also, the invention may use a unidose tip from a compositemanufacturer with a small orifice (14-20 needle gage—an inside diameterin the range of about 0.4 millimeters to about 1.6 millimeters) that canonly be used with heat. This would likely only work if composite isheated.

Referring now to FIG. 20, there is shown another capsule 115 for use ina dental composite dispenser according to the invention. The capsule 115includes a hollow body 116 having an inner surface 117 and a proximalopening 118 at a proximal end 119 of the body 116. An outwardly directedflange 120 is provided at the proximal end 119 of the body 116. Aplunger 121 contacts a movable piston 122 that engages the inner surface117 of the body 116. The piston 122 seals the proximal opening 118 ofthe body 116. The piston 122 and the inner surface 117 pf the body 116define an interior space 123 of the body 116.

The capsule 115 includes a hollow dispensing orifice 124 having apassageway 125 extending from an inlet 126 to an outlet 127. The inlet126 is in fluid communication with the interior space 123 of the body116. A viscous highly filled dental restorative material (not shown) isplaced in the interior space 123 of the body 116. Movement of the piston122 toward the dispensing orifice 124 in direction Q extrudes dentalrestorative material from the outlet 127 of the dispensing orifice 124.The passageway 125 of the dispensing orifice 124 has an inside diameterin the range of about 0.4 millimeters to about 1.8 millimeters,preferably in the range of about 0.6 millimeters to about 1.6millimeters, more preferably in the range of about 0.6 millimeters toabout 1.2 millimeters, and most preferably in the range of about 0.6millimeters to about 1.0 millimeters.

The passageway 125 of the dispensing orifice 124 can have other sizes.The passageway 125 can be in the 1 to 1.5 millimeter range for theinside diameter. The passageway 125 can be in the 0.75 to 1 millimeterdiameter size for the inside diameter. The passageway 125 can be ovoid(about 1×2 millimeters or 1×3 millimeters inside dimension) for class IIcavity preparations or other applications where a non round expressedresin composite shape is desired. The passageway 125 can be about 0.5×3millimeters inside dimension. The ribbon shape is good for restorativefillings as a veneer layer of composite, or a ribbon to line a porcelainonlay or veneer for bonded esthetic porcelain dentistry.

The piston 122 may connected to the plunger 121 which is part of asyringe-type delivery system. The plunger 121 moves the piston 122toward the dispensing orifice 124. Alternatively, the capsule 115 may beinserted in a compartment of a dispensing gun (like dispensing gun 11 ofFIG. 6). The plunger 121 is part of the dispensing gun (like 21 in FIG.6). The plunger 121 moves the piston 122 toward the dispensing orifice124 to extrude dental restorative material from the outlet 127 of thedispensing orifice 124. Optionally, the dispensing gun includes a devicefor multiplying a force applied to the plunger 121 by a user. Thisprovides extra force extrude the viscous highly filled dentalrestorative material through the outlet 127 of the dispensing orifice124. Alternatively, a device for reducing the viscosity of the dentalrestorative material is provided with the capsule 115. For example,resistive heating elements (such as 35 in FIG. 15) can be positioned inthe end section of the dispensing gun adjacent installed capsule 115.The capsules 115 can also be heated in a separate heater before or afterinstallation in the dispensing gun.

The dental restorative material includes a polymerizable (e.g., lightcurable) resin and a filler. Non-limiting examples of suitable resinsinclude acrylate resins, methacrylate resins, and silorane-based resins.Non-limiting examples of suitable fillers include silica, silicateglass, quartz, barium silicate, strontium silicate, barium borosilicate,strontium borosilicate, borosilicate, lithium silicate, lithium aluminasilicate, amorphous silica, calcium phosphate, alumina, zirconia, tinoxide, and titania. The paste composite can include greater than 30% byvolume filler, or greater than 40% by volume filler, or greater than 50%by volume filler, or greater than 60% by volume filler, or greater than70% by volume filler, or greater than 80% by volume filler, or greaterthan 90% by volume filler. Preferably, the dental restorative materialhas a volume shrinkage of 3% or less upon curing, More preferably, thedental restorative material has a volume shrinkage of 2% or less uponcuring. Most preferably, the dental restorative material has a volumeshrinkage of 1% or less upon curing.

Thus, the invention provides methods for the restoration of a decayedportion of an anterior tooth or re-restoration of a previously filledanterior tooth, and also provides dental matrices and composite resindispensers that may be used in the methods for the restoration of adecayed portion of an anterior tooth.

The invention has many advantages. For example, the step down tips andthe heating of the composite allow the dentist to make smaller cavitiesthat would be too small to fill easily with larger tips, especially inlight of the fact that most United States dentists are now usingmagnification (e.g., oculars, operating microscopes and digital videoclinical magnification). Also, the step down tips and/or the heating ofthe composite allow the dentist to more efficiently use an anatomicmatrix. An anatomic matrix has more closed off access. Without a smallerorifice on the dispenser tip, it can be difficult to do injection moldedcomposites as the dentist cannot get the large tip of a larger syringeinto a conservative cavity that has an anatomic matrix that is“pre-wrapped”, impeding the placement of the capsule tip. Without (i)the step down tips and/or (ii) the micro-tip/heated only/paste specificcapsules and/or (iii) the composite heater gun with micro-tip pasteextrusion tips, a dentist could only squirt the paste on to the tooth oron a pad, then scoop it up on a dental instrument and then try to packit manually into the cavity preparation. A dental composite dispenseraccording to the invention heats the composite as the composite isinjected into the cavity preparation, that is, the same dispenser heatsand injects the composite. Those skilled in the art would recognizefurther advantages of the invention.

Although the invention has been described in considerable detail withreference to certain embodiments, one skilled in the art will appreciatethat the present invention can be practiced by other than the describedembodiments, which have been presented for purposes of illustration andnot of limitation. Therefore, the scope of the appended claims shouldnot be limited to the description of the embodiments contained herein.

What is claimed is:
 1. A dental matrix comprising: a non-flat sectionalstrip having a first end and an opposed second end, wherein the stripincludes at least one anatomic feature dimensioned for a surface of ananterior tooth.
 2. The dental matrix of claim 1 wherein: the strip has alength from the first end to the second end such that the strip cancover at least 90 degrees around side surfaces of the anterior toothcovered by the strip.
 3. The dental matrix of claim 1 wherein: thematrix is translucent.
 4. The dental matrix of claim 1 wherein: thestrip is pre-curved and universal for any interproximal surface of anyanterior tooth.
 5. The dental matrix of claim 1 wherein: the matrixincludes a pronounced root-crown interface.
 6. The dental matrix ofclaim 1 wherein: the matrix is side specific for the anterior tooth. 7.The dental matrix of claim 1 wherein: the matrix is tooth specific forthe anterior tooth.
 8. The dental matrix of claim 1 wherein: the matrixis tooth and surface specific for the anterior tooth.
 9. The dentalmatrix of claim 1 wherein: the matrix is fully anatomic for the anteriortooth.
 10. The dental matrix of claim 1 wherein: the matrix isanatomically shaped such that the matrix is self stabilizing and handsfree for the anterior tooth.
 11. The dental matrix of claim 1 wherein:the matrix includes a side flange that extends away from the first end.12. The dental matrix of claim 1 wherein: the strip has a length fromthe first end to the second end such that the strip can cover 360degrees around the side surfaces of the anterior tooth covered by thestrip.
 13. The dental matrix of claim 1 wherein: the strip has a lengthfrom the first end to the second end such that the strip can cover from90 degrees up to 359 degrees around the side surfaces of the anteriortooth covered by the strip.